1. Field of the Invention
The present invention relates to a centralized and networked protection system and method of a regional distribution network, and belongs to the field of electrical power system automation and relay protection.
2. Background of the Invention
To improve the supply reliability of a distribution network, ring network structures have been adopted in today's distribution architecture. In the ring network structure, as over-current protection is dominant, the constant values of the feed line out from substations and main lines of distribution network are hard to set, and neither the constant value nor the time delay can match for the feed line and the main lines. In addition, the access of distributed power supply changes original topological structure of a distribution network from a radiation structure from a single power supply to a mesh structure from multiple power supplies, which brings great effects on relay protection of the distribution network. Presently, the domestic distribution automation mostly uses a recloser and a sectionaliser, and feed-line automation based on communication. However, for important loads, these control manners inevitably have drawbacks like low degree of selection to remove faults, blackout of non-fault sections, high loss of switching devices and long time of fault processing.